Apparatus for the separation of mixtures of substances



R. SIGNER Sept. 29, 1959 APPARATUS FOR THE SEPARATION OF MIXTURES OF SUBSTANCES Original Filed NOV. 5, 1951 3 Sheets-Sheet 1 FIG. 6.

APPARATUS FOR THE SEPARATION OF MIXTURES 0F SUBSTANCES Original Filed Nov. 5, 1951 R. SIGNER Sept. 29, 1959 I5 Sheets-Sheet 2 FIG.3

FIG.8

INVENTOR. E0004; J/fA//Q R. SIGNER Sept. 29, 1959 APPARATUS FOR THE SEPARATION OF MIXTURES OF SUBSTANCES 3 Sheets-Sheet 5 Original Filed Nov. 5, 1951 FIG. IO

INVENTOR. E00 04 F J/fA/d-TQ W? United States Patent APPARATUS FOR THE SEPARATION 0F MIXTURES 0F SUBSTANCES Rudolf Signer, Gnmligen, near Bern, Switzerland Original application November 5, 1951, Serial No. 254,950, now Patent No. 2,765,298, dated October 2, 1956. Divided and this application'October 1, 1956, Serial No. 613,067

7 Claims. (Cl; 23-2705) This application is a division of a copending application Ser. No. 254,950, filed November 5, 1951, now Patent No. 2,765,298.

The present invention is concerned with a process of separating mixtures of substances by counter-current distribution between two liquid immiscible phases and in particular with an apparatus for carrying out this process.

In a separating funnel, mixtures are separated more or less completely by means of two liquid phases which are not-miscible with each other. If the components of a mixture have similar partition coefiicients, many systematically combined shaking operations are necessary to bring about complete separation. There have already been disclosed numerous ingenious pieces ofapparatus with which a limited quantity of material is discontinuously. extracted with repeatedly new portions of both phases.

Furthermore,- there are already known many kinds of apparatus working on the counter-current extraction principle, these being supplied continuously with the mixture to be separated and with two immiscible liquid phases which continuously flow out of the apparatus again and one of which contains one substance or a group of substances while the other contains the other substance or group of substances to an increasing extent. Most of these types of apparatus comprise a large number of alternately arranged chambers with agitating or stirring mechanisms and with separating chambers.

The'liquid phases flowing through such apparatus are alternately mixed in a stirring chamber and again segregated in an adjacent separating chamber. This alternation of thoroughly mixing and separating is repeated as many times as there are chambers. Apparatus of this kind are exceedingly complicated and their performance is not satisfactory. The more intensive the stirring, the more ditficult becomes the systematic advancing of a particular phase in counter-current to the other. The less intensive the stirring, the more incomplete is the adjustment of the partition equilibrium in a chamber and the separating action of the entire apparatus.

It has now been found that the difiiculties known heretofore may be completely overcome if the two phases are brought into intimate contact in adjacently arranged chambers or zones provided with apertures for transport of the phases, while at the same time a substantially uninterrupted phase interface is maintained in the individual chambers, one or both phases flowing in horizontal direc tion from one chamber into the other.

The upper or the lower phase may be left at rest while the other one moves more or less rapidly, or both phases may move with identical or dilferent velocities in opposite directions, or both phases may be allowed to travel with different velocities in the same direction.

According to the present invention, I provide apparatus for separating mixtures of substances by counter-current distribution between two liquid immiscible phases, in which the mixture is introduced into at least one of the Patented Sept. 29, 1959 ICC 2 phases and the two phases are brought into intimate contact for the purpose of adjusting the partition equilibrium in a plurality of adjacently arranged, contiguous chambers or zones communicating with each other through apertures, while a substantially uninterrupted phase interface is maintained in the individual chambers, the phase interface being continuously renewedin the individual chambers by maintaining a constant movement within the individual phases, at least one of the phases being allowed to flow in horizontal direction from one chamber to the next. 7

The intimate contact of the phases in the chambers is necessary for the rapid establishment of the partition equilibrium. This part 'of the process may be compared with the shaking of two phases in a separating funnel where, by the vigorous movement, both phases are split up within each other in the. form of drops and thus brought into intimate contact. In this kind of intimate contact due to the production of drops, comparable with the production of a more or less coarsely dispersed emulsion, the phase interface is very intensely sub-divided.

In:.contrast to the above, according to the present invention, the intimate contact is brought about by maintaining a substantially unbroken, continuous phase interface, .i.e. without appreciable portions of the phases beingsplit up within each other in the form ofdrops. This kind of intimate contact or vigorous mixing of the phases has hitherto not been applied in the comparable counter-current extraction apparatus, obviously because it was assumed that a sufliciently rapid establishment of the partition equilibrium is only attainable by anintense sub-dividing of the phase interface.

From the following. description. of practical embodiments of the apparatus according to the invention and the examples of carrying out the process according to the invention, it is manifest that this kind of phasemixing, which is novel as far as counter-current extraction is concerned, is technically simple to carry out and is highly effective.

It was not to be foreseen, and in fact it is surprising, that the new mode of operation makes it possible for the partition equilibrium of the substances dissolved in the phases to be rapidly established in each individualchamher by adequate renewal of the phase interfaceandfor the cleanly separated phases to flow .into adjacent. chambers. The distribution of thedissolved substances between the phases and the separation of the phases is thus carried out simultaneously in each individual chamber.

Compared with most counter-current extraction apparatus known hitherto, in which two dilferent'pieces of apparatus are required for mixing and for. separating, this means a considerable simplification.

A further considerable advance is. obtained by the intense renewal of the phase interface, without appreciable portions of one phase being divided up in the .other one in the form of drops. The result is, that the clean separation and clean advancing of the phases is extremely facilitated and the formation of troublesome emulsions is made practically impossible.

The apparatus according to the invention comprises a container which is sub-divided bytransverse partitions into a plurality of practically horizontal chambers which are in communication with each other by one or more apertures arranged in each partition, means for introducing two liquid immiscible phasesinto the container, means for discharging these phases at separate places in the container, and means for introducing the'mixture :to be separated into a chamber of the container.

These and other objects of the invention will become further apparent from the following detailed description, reference being made to the accompanying drawings showing preferred embodiments of the invention.

In the drawings:

Fig. 1 is a schematic longitudinal section through a first embodiment of the apparatus;

Fig. 2 is a crosssection of the apparatus taken transversely to Fig. 1;

Fig. 3 is a schematic longitudinal section through a second embodiment of the apparatus;

Fig. 4 is a cross-section on the line AA in Fig. 3;

Fig. 5 is a cross-section on the line BB in Fig. 3;

Fig. 6 is a cross-section on the line CC in Fig. 3;

Figs. 7 and 8 are longitudinal sections supplementary to Fig. 3;

Fig. 9 is a cross-section through a device for charging the apparatus with the mixture to be separated; and

Fig. 10 is an arrangement of an outlet device.

In Fig 1, 1 is a horizontal hollow cylinder rotatable about its axis and sub-divided into a plurality of chambers or zones by transverse partitions 2. The transverse partitions are provided with small apertures or perforations 2a. The heavier phase is denoted by 3 and the lighter phase by 4. 5 is a funnel for continuously introducing the heavier phase into the left-hand end chamber of the cylinder. 6 is a siphon for leading off the heavier phase from the right-hand end chamber to a receiver 7. 8 is a funnel for continuously introducing the lighter phase into the right-hand end chamber. 9 is a siphon for leading oif the lighter phase from the left-hand end chamber to a receiver 10. 11 is a funnel for continuously introducing the mixture to be separated into a central chamber of the cylinder. So as not to interfere with rotation of the cylinder, the conduit leading from funnel 11 extends through central openings in the partitions 2, which are larger than apertures 2a.

In Fig. 2, the reference numerals 1, 2, 2a, 3 and 4 designate parts corresponding to those of Fig. 1.

When working, the apparatus shown in Figs. 1 and 2 operates in such a way that through the funnel 5 the heavy phase 3 flows continuously into the left-hand end chamber and flows out through the siphon 6 into the receiver 7, while through the funnel 8 the lighter phase i 4 flows continuously into the right-hand end chamber and flows through the siphon 9 out of the left-hand end chamber. Thus the two phases are each divided into a plurality of parts and traverse the cylinder throughout its entire length in opposite directions by flowing A through the communication-restricting apertures 2a from one chamber into the next.

The cylinder 1 rotates slowly about its axis. This rotation results in a complicated arcuate agitation movement of the two phases in a plane substantially perpendicular to the axis of the agitator, i.e. the cylinder, thus causing a continuous intensive new formation of the interface between the two phases, without producing an emulsification of the two phases. The mixture to be separated flows continuously through the funnel 11 into a central chamber of the cylinder.

Due to the movement in the two phases, the components of the mixture are distributed between the two phases according to the partition coefiicients between the heavy and light phases. The partition equilibrium very rapidly establishes itself owing to the movement in the liquid phases. A given component of the mixture is enriched predominantly in one or other of the receivers 10 and 7 according to its partition coefiicient between the two phases and the speed of flow of the phases.

In the embodiment of the apparatus according to the invention illustrated in Fig. 3, the cylinder 1 is likewise arranged horizontally and sub-divided into chambers by transverse partitions 2. The transverse partitions 2 are provided with apertures 2a giving passage to the phases, of which the heavier one is denoted by 3 and the lighter one by 4. 'In this case, however, the cylinder 1 is arranged to be stationary. Each chamber contains a rotatable disc 12, on which baffles (not shown) can also be arranged. The discs 12 of all chambers are mounted 4 on a spindle 13 rotatably mounted coaxially with the cylinder.

The heavy phase is delivered through the funnel 5 (Fig. 4) into the first chamber of the cylinder and let out of the last chamber into the receiver 7 by means of the siphon 6 (Fig. 5). The light phase passes through the funnel 8 (Fig. 5) into the last chamber of the cylinder and is delivered into the receiver 10 out of the first chamber of the cylinder by the siphon 9 (Fig. 4).

The mixture to be separated is continuously introduced through a funnel 11 (Fig. 6) laterally arranged on the cylinder at a suitable place.

The speed of rotation of the agitator discs 12 on the spindle 13 is kept so low that substantially no drops of one of the two phases are formed in the other one. In order to observe this, sight glasses 14 (Fig. 3) are provided in the end faces of the cylinder. They also enable the level of the two phases to be observed.

Even at a low speed of rotation at which there is still no release of drops and no emulsifying of one phase in the other, the rotating discs 12 bring about an astonishingly rapid adjustment of the partition equilibrium of each dissolved molecule type in each chamber.

This very favorable action of the discs is due to two reasons. In the first place a rapid liquid movement takes place in both phases in the vicinity of the phase interface, so that new volume elements of both liquids repeatedly come into contact with each other. Then again, that one of the two phases which has the higher wetting power with respect to the material of the disc, clings to the disc in a thin film and is drawn along an arcuate path in a vertical plane through the other phase.

The apertures from chamber to chamber in the transverse partitions are made sufficiently large to prevent any appreciable congestion or damming back of the phases. In the first embodiment of the apparatus with the rotating cylinder in accordance with Figs. 1 and 2, the number and magnitude of the apertures may be varied and chosen in accordance with the viscosity and speed of flow of the phases.

In the embodiment with the stationary cylinder and rotating discs according to Figures 3-6, those surface portions in the partitions contacted by the individual phases may be provided with one or more openings, the size of which is also chosen in accordance with the viscosity of the phases and their velocity of fiow. On the other hand, one or more openings may be provided in only one of the surface portions against which the phases make contact, so that one phase is at rest whilst the other phase flows.

When the openings are large, the phase interfaces in all chambers are practically at the same level as indicated in Figs. 1 and 3. With very small openings and high speeds of flow, the phase level in the various chambers disposes itself as shown in Fig. 7. In this case the lighter phase flows from the left to the right and the heavier one from the right to the left. The countercurrent flow of the two phases, and consequently the proper functioning of the apparatus, ceases. The openings must therefore be enlarged to such an extent that both phases are present in sufliciently high layers in the two end chambers of the cylinder to permit them to be drawn off by the siphons.

When large openings are used, the damming of the phases can be easily avoided completely but the separating efficiency of the apparatus falls off rapidly. A prejudicial equalization of concentration between adjacent chambers takes place through the large openings. The number and size of the openings is correctly set to the viscosity and speed of flow of the phases when the bottom phase is in a slightly stepped formation. Good results are obtained, if the level of the bottom phase at the end where it flows into the cylinder is about two thirds of the total height of both phases and about one of the total height of both phases at the outflow end.

" In the: example with the stationary cylinder and rotating discs according to Fig. 3, the phase damming may ranged parallel with the chamber walls and they there- I fore give rise to a pump action which transmits itself from one chamber to the other.

This pump action depends, among other things, on the speed of rotation, the dimensions of the chambers, the viscosity of the phases, etc. By a suitable choice of the angle a, it is possible to compensate the phase damming empirically when the openings in the transverse partitions are very small in size. This gives the apparatus an effective number of stages amounting to almost 100% of. the effective number of chambers.

While preserving the fundamental idea of the invention, the individual parts of the apparatus may be very differently constructed. The number of chambers may be large or small. When the partition coeificients vof the components of a mixture are very diflerent, a small number of chambers is suflicient to produce complete separation. If the partition coeflicients are similar, a large number of chambers is necessary. The chambers may all be disposed at the same level or slightly stepped.

The dimensions of the apparatus depend upon the quantities of mixture to be separated per unit of time. For small quantities, chamber volumes of a few cm. are sufficient. For large quantities, chamber volumes of several litres are necessary. Even with phases of considerable depth, e.g. of several dms, the partition equilibrium still establishes itself very rapidly owing to the continual renewal of the phase interface.

The agitators may take the form of propellers with a slight pitch. This results in a pump action which diminishes the phase damming. It is also possible to employ double propellers with different effective radii. One propeller dips only into the upper phase and pro 'duces a movement in one direction. The other propeller has a large radiusand gives rise to a movement in opposite direction in the lower phase.

The separating procedure according to the invention maybe carried out in a diversity of ways.

The mixture to be separated may be introduced ,continuously into a chamber placed either in the middle of the cylinder or more or less towards one or the other end of same. The mixture is then separated continuously into two fractions, each of which is dissolved in a respective phase, emerging at one corresponding end of the apparatus.

The dividing up of the molecule types in the .two fractions depends on their partition coeflici'ents in the two phases, the volumes of the two phases in each chamber, the speed of flow of the two phases, the total number of the chambers and the place where the mixture is introduced. A suitable arrangement for introducing the mixture to be separated is shown in Fig. 9.

A vessel contains the solution of the mixture in the heavier phase. The vessel 15 is connected to a chamber of the cylinder by means of the tubes 16 and 17. If the density of the mixture is different from that of the dissolving phase, a circulation of the solution from the vessel 15 to the chamber and from the latter back to the vessel, takes place. The arrows in Fig. 9 indicate the direction of movement in the case in which the density of the mixture to be separated is higher than that of the dissolving phase.

The dissolved material distributes itself partially in .-the two phases and is moved through the cylinder while the remaining portion of the dissolved material returns coefiicient should pass into the receiver.

into the vessel. The circulation continues until the cofi centration of the mixture; to be separated in the phase has become infinitesimally small in the vessel 15;

When this mode of introducing themixture is employed, the rateo-f fl'ow of that phasein which the'mixture is introducedremains constant through the entirecylinder. This is not the case with the method of introduction indicated in Fig. 1

A simpler method of introducing the mixture "is "provided by using afunnel 1 1, as illustrated in Fig. 6.

The mixture may be added in the-dry'st'ateor as-a more or less concentrated solution inthe corresponding phase.

The new extraction. procedure may also be used to enable a mixture of several components with different partition coeflicients. to be separated successively into its individual components. This application of the invention is analogous tothe method in which amixture of manycomponents with differentboiling points is separated by means of a distillation column, in which the most volatile components are separated off first of all and thenthe second most volatile, and so on.

The mixture, dissolved in one phase, is allowed to flow out of a container, for example of the kind shown in Fig. 9, into the corresponding phase in the first chamber of the apparatus and it is pumped out of this chamber back again into the container. A continuous circulation of the dissolved mixture from the container to the first chamber and from the latter back to the container is maintained.

The cylinder iscontinuously traversed from the last to the first chamber by fresh quantities of the same phase .as is used for dissolving the mixture to be separated, so that the total volume of liquid in circulation from the chamber to the container and back, is increased. In order to maintain a constant volume of fluid, it is therefore necessary to interpose in this circulation a means for continuously removing (for exampleby evaporation) as much of the phase as flows in through the cylinder.

The second phase flows from the first chamber to the last chamber of the cylinder and passes from the latter into a receptacle.

The greater the ratio of the rate of flow of the phase flowing toward-the mixture to be separated with respect to the phase flowing toward the receiver, the smaller is the probability that a component with a particular partition If this ratio of speeds of flow varies from 00 through 1 to 0, all components pass successively into the receiver. The sharpness of separation naturally depends uponthe number of chambers and the difference between adjacent partition coeflicients.

Ifsmall quantities of a mixture are to be separated, the procedure can be carried out very simply with .a flowing and a stationary phase. The entire mixture is introduced .once and for all into one of the two end chambers in the stationary phase. The flowing phase is introduced into this same end chamber so that the various components of the mixture in the flowing phase successively emerge, cleanly separated, from the other end chamber, provided that the number of chambers is sutficiently large and the partition coeflicients of the components are sufficiently far apart.

With this mode of operation it is expedient to saturate the flowing phase with the stationary phase before entry into the apparatus.

The speeds of flow of both phases must be varied within wide limits according to the separation to be carried out. In order to keep the speeds of flow constant during an entire separation operation it has been found practical to effect theinflow into the funnels 5 and 8 (Figs. 1 and'S) out of Mariette flasks. With the latter, by a suitable choice of thehydrostatic pressure and the resistancein the outlet tube of-the Mariotte flask, it is possibleto varythe rate offiow :within wide limits and .to keep it'constan-t.

In the case of apparatus with a large number of chambers, particular care must be given to the level of the two phases. It is ensured by the correct positioning of the siphons 6 and 9 (Figs. 1, 4 and It has been found practicable to operate the fine adjustment of the siphons with an arrangement as shown in Fig. 10. The siphon 20 is secured to a lever whose-fulcrum 19 is situated at the immersion end of the siphon and which can be adjusted by a screw 18. When the screw 18 of the siphon is operated, the immersion end of the siphon remains stationary whereas the outlet end 20 is raised or lowered by a very little distance.

When there are considerable temperature fluctuations, fine droplets from one phase separate out into another phase. The result is that the sharpness of separation suffers. It is therefore of advantage to operate at constant temperature.

The excellent separation effects which are attainable with the new apparatus and procedure are comparable with the results of paper chromatography. Compared with this method, which is now much in use and is very efiicient from the point of view of separating action, the procedure according to the invention has the advantage that it is very suitable for separating larger quantities of substances for preparatory work in the laboratory and for operations on an industrial scale.

In order that the invention may be well understood, the following examples are given only as illustrations:

EXAMPLE 1 Separating a mixture of leucine and valine with butanol/water Apparatus with stationary cylinder and discs as stirring members (in accordance with Fig. 3).

Number of chambers 13 Length of cylinder cm Radius of cylinder cm 5 Speed of stirring discs of 4.8 cm. radius: revolutions per min.

Apertures in partitions: 2 circular orifices of 0.5 mm. radius in those surface portions of the chamber partitions with which the upper phase comes in contact. The lower phase does not flow. There are no apertures in those surface portions of the partitions with which the lower phase comes in contact.

Upper phase: 10 ccs. butanol, saturated with water, in each chamber. Rate of flow: 60 ccs./hr.

Lower phase: 2 ccs. water, saturated with butanol, in each chamber. Rate of flow: 0 cc./hr.

Mixture: 0.089 millimol leucine and 0.122 millimol valine, fed at once into the first chamber.

Fractions of 10 ccs. are caught. The concentration of leucine and valine in the butanol will be apparent from the following:

Quantities of amino acids Leucine Vnline Fractions Percent Percent with rewith respeet to spect to the quanthe quan- Milhmols tity pres- Millimols tity present in the ent in the starting starting mixture mixture 0-140 ccs 0 0 0 I 0 140-300 cos... 0. 037 42 0.005 4 300-400 ccs- 0. 041 46 0. 026 21 400 500 ccs- 0. 010 ll 0. 041 84 500-600 ccs. 0.001 1 0.032 26 0 0 0. 014 12 0 0 0. 004 3 Taking the partition coeflicients (concentration in the butanol to concentration in the water), 0.136 for leucine and 0.072 for valine, and the volume ratio of 10.,ccs. upper phase to 2 ccs. lower phase, and assuming a discontinuous shaking with 10 and 13 separating funnels respectively, the figures of the following table have been computed, these being compared with the observed values of this example.

Within the limits of error, the observed concentrations of both amino acids agree with those computed for 13 separating funnels. However when 10 separating funnels are used, considerable differences occur between the observed and computed values. The apparatus of Example 1 thus operates with an effectual chamber number of over of the 13 effective chambers.

It is easy to construct apparatus with a much greater number of chambers than 13. With a chamber number of 40, the separation of leucine and valine is complete. First of all the entire leucine passes into the receiver, then the amino acid concentration in the emerging butanol sinks to zero. Thereupon the valine comes out.

EXAMPLE 2 Separating a mixture of leucine and alanine with phenol/ water Apparatus with stationary cylinder and discs as stirring members, as in Example 1.

Speed of discs: 14.5 revolutions per min.

Apertures in the partitions: 1 circular orifice of 0.5 mm. radius in those surface portions with which the upper phase comes into contact.

Upper phase: 4.5 ccs. wvater, saturated with phenol, in each chamber, rate of flow 18 ccs./hr.

Lower phase: 6.5 ccs. phenol, saturated with water, in each chamber, rate of flow 0 ccs./hr.

Mixture: 50 mg. leucine and 50 mg. alanine are fed at once into the first chamber.

Fractions of 5 cos. are caught. After 50 ccs. of the upper phase have flowed out of the apparatus, pure alanine emerges. In the fractions 50-70 ccs. there are 15 mg. of alanine free from leucine. In the fraction -105 ccs. both amino acids are to be found in the same concentration. With ccs., the entire alanine is washed out of the apparatus. In the fractions 155- ccs. there are 20 mg. of leucine, free from alanine.

EXAMPLE 3 Separating casein into aand ,B-casein Apparatus with stationary cylinder and discs as stirring members, as in Example 1.

Speed of stirring discs: 3 revolutions per minute.

Apertures in the partitions: 1 circular orifice of 0.5 mm. radius in those surface portions with which the lower phase makes contact.

Phases:

4 parts by volume of water 7 parts by volume of glacial acetic acid 3 parts by volume of phenol, saturated with water 5 parts by volume of acetylene tetrachloride yield a two-phase system with very low interfacial tension.

Upper phase: 8 00s. in each chamber, rate of flow, 0 ccs./hr.

game

Lower phase: 3 ccs. in each chamber, rate of flow, 4 ccs./hr.

Mixture: 100'mg. casein according to Hammarstemfed at once into the first chamber.

Fractions of 5 ccs. are caught. With the fractions from 40-75 ccs., pure fl-casein emerges in a total quantity of 14 mg., the maximum concentration occurring in the fraction 55-60 ccs. With the fractions from 80-200 ccs., pure a-casein emerges, the maximum concentration occurring in the fraction 105-110 ccs. The separation of the casein into ocand ,B-casein could hitherto only be accomplished by two tedious methods which are both unsuitable for the product-ion of considerable quantifies of, 00- and B-casein. On the one hand, small. quantities of casein may be split up electrop'horetically. on the other hand, aand fl casein may be collected by repeated fractionated precipitation. The method described in EX- airiple 3 supplies both caseins in pure form in one operation.

EXAMPLE 4 Continuous counter-current extraction of a concentrated albumen hydrolysate with butanol/ water Apparatus as in the Examples 1-3.

Speed of the stirring discs: 27 revolutions per minute.

Openings in the partitions: 1 circular aperture of 0.5 mm. radius both in those surface portions bounding the lower phase as well as in those bounding the upper phase.

Upper phase: Butanol, saturated with water, rate of flow 45 ccs./hr.; delivered from Mariette flask.

Lower phase: Water, saturated with butanol, rate of flow 7 ccs./hr.; delivered from Mariotte flask.

Mixture: Albumen hydrolysate which is introduced from a large container, as in Fig. 9, connected to the seventh chamber. Initial concentration of the circulating mixture, 30 g. amino acids and 10 g: sodium chloride in 100 ccs.

Butanol fraction: Pure phenylalanine.

Aqueous fraction: Little phenylalanine, together with all other amino acids and common salt. Dry content,

9 g. in 100 ccs.

EXAMPLE 5 Continuous counter-current extraction of a diluted albumen hydrolysate with butanol/w'ater EXAMPLE 6 Dividing up an albumen hydrolysate into three fractions by twice-repeated counter-current extraction with phenol/ water Apparatus as in the Examples 1-3.

Apertures in the partitions: an opening with 1 mm. radius in those surface portions with which the phenol phase comes into contact, an opening of 0.5 mm. radius in those surface portions with which the aqueous phase comes into contact.

FIRST EXTRACTION Upper phase: Water, saturated with phenol, rate of flow, l0 ccs./hr. Lower phase: flow, 30 ccs./hr.

Speed of stirring discs: 14 revolutions per minute. Mixture: Albumen hydrolysate, which is fed from a container as in Fig. 9, connected to the seventh chamber.

Volume of the circulating solution 350 ccs.

Phenol, saturated with water, rate of Dry content of the mixture 6.0 g. amino acids and 0.5 g. sodium chloride.

Duration of extraction: 40 hrs. The concentration in the container, out of which the mixture is fed, practically sinks to zero.

Fractions: In the phenol fraction, there are tobe found-off the monoarnino-monocarboxylic acids-proline, leucine, phenylalanine and valine as well as a portion of the alanine and threonine. In the aqu'eousfraction there is to be found the other portion of alanine and threonine, as well as the whole of the glycine, serine and all water-soluble amino acids as well as the common salt: SECOND EXTRACTION w Upper phase: Water, saturated with phenol, rate of flow, 20 ccs./hr.

Lower phase: Phenol, saturated with water, rate of flow, 20 ccs./hr.

Speed of the stirring discs: 11 revolutions per minute.

7 Mixture: Amino acids of the phenol fraction of the first extraction, dissolved in 50 ccs. phenol; introduction of the mixture into the seventh chamber out of the container according to Fig. 9.

Duration of extraction: 50 hrs. The concentration in the container out of which the mixture is fed, sinks to zero.

Fractions: In the phenol fraction there are to be 'found--of the neutral amino acidsthe' proline, leucine, phenylalanine and a portion of the valine, in the aqueous fraction there is to be found the other portion of the valine and the entire alanine and threonine.

EXAMPLE 7 Dividing up an albumen hydrolysate by counter-current extractions into many fractions with butanol/water Apparatus as in Example 1.

Speed of the stirring discs: 27 revolutions per minute.

Apertures in the partitions: l circular orifice of 0.5 mm. radius in those surface portions with which the upper phase comes into contact; 1 circular orifice of 0.25 mm. radius in those surface portions with which the lower phase comes into contact. I

Upper phase: Butanol, saturated with water.

Lower phase: Water, saturated with butanol.

Mixture: Albumen hydrolysate with 3.8 g. amino acids and 1.2 g. sodium chloride in ccs. lower phase. The mixture circulates from the first chamber to a storage vessel, through a pump, an evaporator and back ,to the first chamber. Pump and evaporator are of the type described in Helv. Chim. Acta, vol. 29, page 1984*(1946). The butanol phase passes into the first chamber and out of the last one into a receiver. The aqueous phase passes into the last chamber and unites itself with the circulating mixture in the firstchamber.

Fractions: Every 24 hours the butanol receiver was changed and its contents analyzed. The composition of the fractions and the corresponding rates of flow of the phases will be gathered from the following table:

The residue in the aqueous phase is free from'phenylalanine, valine, leucine. It still contains a very small '11 amount of proline and the water-soluble amino acids together with common salt.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, What is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for separating from each other the components of a mixture of substances by means of two immiscible liquid phases of different specific gravities and of different respective partition coeficients with re spect to at least one of said substances, comprising a horizontal cylinder journaled for rotation about its own axis, and having end walls at its opposite ends, a plurality of annular partitions arranged within and spaced from one another axially of said cylinder intermediate said end walls to define between the latter and within said cylinder a plurality of individual chambers, each of said partitions being provided with a plurality of apertures located at equal radial distances from said axis of said cylinder and spaced from one another circumferentially of the respective portion, means communicating with one of said chambers of said cylinder for introducing thereinto said mixture of substances to be separated, means located adjacent one end of said cylinder and communicating with the respective end chamber thereof for introducing one of said liquid phases into said respective end chamber, means located adjacent the other end of said cylinder and communicating with the other end chamber thereof for introducing into the latter the other of said liquid phases, whereby the heavier one of said phases settles to the bottom of said cylinder, while the lighter phase floats on top of said one phase and is separated therefrom by an interface substantially continuous within each chamber, and respective means communicating with said end chambers for removing from each of said end chambers that one of said phases introduced into the other end chamber together with the substances of said mixture dissolved therein respectively.

2. Apparatus according to claim 1, there being provided four apertures in each partition, said apertures being arranged in pairs on perpendicular diameters of the respective partitions.

3. Apparatus according to claim 2, each partition being provided with four additional apertures arranged in pairs on said perpendicular diameters and located at equal distances from said axis of said cylinder, the spacing between each two apertures located on the same radius of the respective partition being predetermined to ensure that said phase interfaces in said chambers are located at a level between the lowest two apertures when said cylinder is stationary.

4. Apparatus according to claim 1, said means for introducing said mixture of substances into said cylinder being in communication with the central one of said chambers.

5. Apparatus for separating from each other the components of a mixture of substances by means of two immiscible liquids of respective heavy and lighter phases and of different respective partition coeflicients with respect to at least one of said substances contained in said mixture; comprising a substantially horizontal hollow cylinder having two at least partially closed first and second ends and a longitudinal axis for rotation of the cylinder thereabout, a plurality of partitions transversely arranged to said longitudinal axis within said cylinder to subdivide the latter into a plurality of rotatable chambers disposed directly adjacent each other, each of said partitions being provided with at least one aperture therethrough communicating between respective adjacent chambers, first conduit means for introducing a first of said immiscible liquids which has a relatively heavy phase into one of said chambers and located to reach into said first end of said cylinder, first siphon means operatively communicating with said cylinder for leading off into a first receptacle said heavy phase from another of said chambers located at said second end of said cylinder, second conduit means for introducing a second of said immiscible liquids which has a relatively lighter phase into said other chamber and located to reach into said second end of said cylinder, second siphon means operatively communicating with said cylinder for leading off into a second receptacle said lighter phase from said one chamber located at said first end of said cylinder, and a third conduit means extending through predetermined openings provided in said partitions and communicating with a predetermined chamber positioned between and remote from said chambers located at said ends of said cylinder for introducing into said predetermined chamber said mixture of substances to be separated, whereby during the rotation of said cylinder said heavy and lighter phases will each be divided into a plurality of parts which will flow through said apertures in said partitions and as heavy and lighter phases being repeatedly both mixed and stratified in each of said chambers, will traverse the entire length of said cylinder in opposite directions to each other and whereby said mixture of substances will be divided into components thereof, said components of said mixture being thereby distributed between said parts of said heavy and lighter phases according to said respective partition coefficients.

6. In an apparatus for separating from each other the components of a mixture of substances by means of two immiscible liquid phases of respective predetermined viscosities and of respective heavy and lighter phases; a substantially horizontal cylinder for containing said liquid phases while said phases remain in mutual contact, means operatively connected to said cylinder for causing a relative flow movement of said respective liquid phases at a predetermined rate relative to said cylinder, a plurality of transverse partitions in said horizontal cylinder and having perforations formed therein, whereby said cylinder is subdivided thereacross into a series of individual chambers separated by said partitions and in communication with each other through predetermined perforations of said partitions, said perforations being formed in each of said partitions in such number and size in relation to said predetermined viscosities and to said flow movement of said liquid phases so as to maintain said liquid of heavy phase in a slightly stepped formation in said series of individual chambers, respective means adjacent opposed ends of said cylinder for introducing into said cylinder said two immiscible liquid phases, respective means located adjacent said respective introducing means for discharging said phases from said cylinder and means for delivering said mixture into a predetermined chamber of said cylinder, whereby a distribution of said substances between said phases and the separation of said phases will be carried out simultaneously in each individual chamber.

7. Apparatus for separating from each other the components of a mixture of substances by means of two immiscible liquids of respective heavy and lighter phases and of different respective partition coefficients with respect to at least one of said substances contained in said mixture; comprising a substantially horizontal hollow cylinder having two at least partially closed first and second ends and a-longitudinal axis and being mounted for rotation thereabout, a plurality of perforated partitions transversely arranged to said longitudinal axis within said cylinder to subdivide the latter into a plurality of chambers disposed directly adjacent each other, said partitions each being further provided with a central opening larger than the perforations of said partitions, the perforations being spaced from said central opening, first conduit means for introducing a first of said immiscible liquids which has a relatively heavy phase into one of said chambers and located to reach into said first nd Of said cylinder, first siphon means operatively com- 13 municating with said cylinder for leading 0E into a first receptacle said heavy phase from another of said chambers located at said second end of said cylinder, second conduit means for introducing a second of said immiscible liquids which has a relatively lighter phase into said other chamber and located to reach into said second end of said cylinder, second siphon means operatively communicating with said cylinder for leading ofi into a second receptacle said lighter phase from said one chamber located at said first end of said cylinder, and third conduit means extending through at least several of said partitions via said central openings therein to reach into 14 a predetermined chamber positioned between and remote from said chambers located at said ends of said cylinder for introducing into said predetermined chamber said mixture of substances to be separated.

References Cited in the file of this patent UNITED STATES PATENTS 1,312,488 Leaver Aug. 5, 1919 10 2,154,713 Van Wijk et al Apr. 18, 1939 2,266,521 Van Dijck Dec. 16, 1941 2,689,783 Marullo Sept. 21, 1954 

1. APPARATUS FOR SEPARATING FROM EACH OTHER THE COMPONENTS OF A MIXTURE OF SUBSTANCES BY MEANS OF TWO IMMISCIBLE LIQUID PHASE OF DIFFERENT SPECIFC GRAVITIES AND OF DIFFERENT RESPECTIVE PARTITION COEFFICIENTS WITH RESPECT TO AT LEAST ONE OF SAID SUBSTANCES, COMPRISING A HORIZONTAL CYLINDER JOURNALED FOR ROTATION ABOUT ITS OWN AXIS, AND HAVING ENDS WALL AT ITS OPPOSIT ENDS, A PLURALITY OF ANNULAR PARTITIONS ARRANGES WITHIN AND SPACED FROM ONE ANOTHER AXIALLY OF SAID CYLINDER INTERMEDIATE SAID END WALLS TO DEFINE BETWEEN THE LATTER AND WITHIN SAID CYLINDER A PLURALITY OF INDIVIDUAL CHAMBERS, EACH OF SAID PARTITIONS BEING PROVIDED WITH A PLURALITY OF APERTURES LOCATED AT EQUAL RADIAL DISTANCES FROM SAID AXIS OF SAID CYLINDER AND SPACED FROM ONE ANOTHER CIRCUMFERENTIALLY OF THE RESPECTIVE PORTION, MEANS COMMUNICATING WITH ONE OF SAID CHAMBERS OF SAID CYLINDER FOR INTRODUCING THEREINTO SAID MIXTURE OF SUBSTANCE TO BE SEPARATED, MEANS LOCATED ADJACENT ONE END OF SAID CYLINDER AND COMMUNICATING WITH THE RESPECTIVE END CHAMBER THEREOF FOR INTRODUCING ONE OF SAID LIQUID PHASE INTO SAID RESPECTIVE END CHAMBER, MEANS LOCATED ADJACENT THE OTHER END OF SAID CYLINDER AND COMMUNICATING WITH THE OTHER END CHAMBER THEREOF FOR INTRODUCING INTO THE LATTER THE OTHER OF SAID LIQUID PHASES, WHEREBY THE HEAVIER ONE OF SAID PHASES SETTLES TO THE BOTTOM OF SAID CYLINDER WHILE THE LIGHTER PHASE FLOATS ON TOP OF SAID ONE PHASE AND IS SEPARATED THEREFROM BY AN INTERFACE SUBSTANTIALLY CONTINUOUS WITHIN EACH CHAMBER, AND RESPECTIVE MEANS COMMUNICATING WITH SAID END CHAMBERS FOR REMOVING FROM EACH OF SAID END CHAMBER THAT ONE OF SAID PHASE INTRODUCED INTO THE OTHER END CHAMBER TOGETHER WITH THE SUBSTANCES OF SAID MIXTURE DISSOLVED THEREIN RESPECTIVELY. 